Answer:
Valence electrons are outer shell electrons with an atom and can participate in the formation of chemical bonds. In single covalent bonds, typically both atoms in the bond contribute one valence electron in order to form a shared pair. The ground state of an atom is the lowest energy state of the atom.
20 POINTS: Why it's important for science fair participants to not only create an informative and attractive presentation, but also to detail their information, ideas, and research in a science report.
Answer:
To show what they know!
Explanation:
If you're not showing how you did your experiment thoroughly, then nobody will understand what you did! For instance, if you spent 2 weeks studying really hard about how music affects different kinds of animals, and only put down that music affects animals and no showing your work. Then no one will know how much effort and work you put into it! If you put all the minor details into the presentation, then more than likely everyone will know where your coming from!
Hope this helps! Plz mark as brainliest!
Question 4 (2 points)
Manganese-56 decays by beta emission and has a half life of 2.6 hours. If a sample
is analyzed and found to contain 6.25% parent isotopes and 93.75% daughter
isotopes, what must the age of the sample be?
Answer:
10.4 hours
Explanation:
Now from;
0.693/t1/2 = 2.303/t log (No/N)
t1/2= half life of the radioactive isotope
t = age of the radioactive isotope
No= Original amount of radioactive isotope
N= amount of radioactive isotope left after time t
Substituting values;
N = 0.0625No
0.693/2.6 = 2.303/t log (No/0.0625No)
0.693/2.6 = 2.303/t log (1/0.0625)
0.267 = 2.303/t * log 16
0.267 = 2.773/t
t = 2.773/0.267
t = 10.4 hours
Thank you it means alot if you help :)!
Answer:
10.Semi-Solid
11.Liquid
12.Solid
13:Semi-Solid
When dissolving a gas, an increase in pressure will result in a(n) ______________ in solubility.
Which element is in the lanthanide family?
Answer:
The 15 elements, together with their chemical symbols, are lanthanum (La)
Answer:
PM Promethium
Explanation:
Explain how the copper could be in the lake sample near the picnic area but not have been detected by this test.
Answer:
May be the instrument is incorrect or may be error in it.
Explanation:
The copper have not been detected by this test because the test may be not for the detection of copper, may be it is used for identification of another minerals. If there is copper in the lake sample but can't be detected in the test so it means that the instrument which is used for detection is not the right one or having error in that instrument. Every mineral has a specific type of instrument that detect its presence, if we use incorrect instrument for the mineral then we can't detect the presence of that specific mineral.
How many moles are 2.20 x 10^25 atoms of zinc?
Please answer quick will give Brainliest!
Answer:
1.3244 x 10⁴⁹ atoms of zinc
Explanation:
2.20 x 10²⁵ moles
To convert from moles to atoms, we multiply by Avogadro's Number, 6.02 x 10²³
2.20 x 10²⁵ • 6.02 x 10²³
= 1.3244 x 10⁴⁹ atoms of zinc
Hope this helps!
22 Determine the molar mass of an unknown gas that has a volume of 72.5 mL at a temperature of 68C, and a pressure of 0.980 atm and a mass of 0.207 g.
Answer:
81.5g/mol
Explanation:
Molar mass is the ratio between mass of a substance (In this case, 0.207g) and moles presents in this mass.
To solve this question we must find the moles of the gas in order to obtain the molar mass using:
PV = nRT
PV / RT = n
Where P is pressure = 0.980atm
V is volume in Liters = 0.0725L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 68°C + 273.15 = 341.15K
0.980atm*0.0725L / 0.082atmL/molK*341.15K = n
2.54x10⁻³ moles = n
Thus, the molar mass of the gas is:
0.207g / 2.54x10⁻³ moles
81.5g/molWhich of these acid dissociates completely in aqueous solution?
A- Acetic acid
B- Citric acid
C- НСІ
D- Carbonic acid
Answer:
HCl
Explanation:
is a strong acI'd,,By contrast a weak acid like acetic acid (CH3COOH) does not dissociate well in water
HELP MEEEEEEE PLSSS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1 As distance increases between a rocket ship and the ground, gravitational force remains the same decreases increases pushes less
Answer:
decreases
Explanation:
Gravirational force is directly proportional to the mass and inversely proportional to the distance.(Newton's law of gravitation)
An electron is a positively charged particle inside of an atom, just like the proton.
True
False
Answer:
no it's is false because an electron have negative charges and it is not inside the atom and it is found out side the nucleus
molecular mass meaning in chemistry?
Answer:
Molecular mass is a number equal to the sum of the atomic masses of the atoms in a molecule.
Explanation:
The molecular mass gives the mass of a molecule relative to that of the 12 C atom, which is taken to have a mass of 12. Hence why Molecular mass is a number equal to the sum of the atomic masses of the atoms in a molecule.
Zeke knows that there are several layers of sediment underneath his town. The top layer is soil, the next layer is clay, and the next layer is made up of gravel. He suspects that polluted water from a nearby mine is passing through one of these layers and making it into a local river. What could Zeke do to figure out how the polluted water might be moving from the mine to the river? A. He could build a model of the mine and test how deep it can go before it collapses. B. He could remove water from the mine and test it for certain pollutants. C. He could build a model of the soil layers and test if water passes through any of them. D. He could pour polluted water on the ground and test how long it takes for it to reach the river.
Answer:
He could add a model of soil layers.
Explanation: C
In an ecosystem where water from mine is polluting river it can be tested by building a model of the soil layers and test if water passes through any of them.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
Learn more about ecosystem,here:
https://brainly.com/question/13979184
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1. Complete the balanced dissociation equation for the compound below. If the compound does not dissociate, write NR after the reaction arrow.
(NH4)2S(s) -> ______
2. Write the balanced NET ionic equation for the reaction when Al(NO₃)₃ and Na₃PO₄ are mixed in aqueous solution. If no reaction occurs, write only NR.
Answer:
1. (NH₄)₂S(s) -----> NH₄+(aq) + S²-(aq)
2. Al³+ (aq) + PO₄³+ (aq) ----> AlPO₄ (s)
Explanation:
The dissociation of ammonium sulphide, (NH₄)₂S when dissolved in water is given in the equation below:
(NH₄)₂S(s) -----> NH₄+(aq) + S²-(aq)
However very little S²- ions are present in solution due to the very basic nature of the S²- ion (Kb = 1 x 105).
The ammonium ion being a better proton donor than water, donates a proton to sulphide ion to form hydrosulphide ion which exists in equilibrium with aqueous ammonia.
S²- (aq) + NH₄+ (aq) ⇌ SH- (aq) + NH₃ (aq)
Aqueous solutions of ammonium sulfide are smelly due to the release of hydrogen sulfide and ammonia, hence, their use in making stink bombs.
2. The reaction between aluminium nitrate and sodium phosphatein aqueous solution is a double decomposition reaction whish results in the precipitation of insoluble aluminium phosphate. The equation of the reaction is given below :
Al(NO₃)₃ (aq) + Na₃PO₄ (aq) ----> AlPO₄ (s) + 3 NaNO₃ (aq)
The net ionic equation is given below:
Al³+ (aq) + PO₄³+ (aq) ----> AlPO₄ (s)
Just as all the organs in a system work together, the various body
systems work together in a healthy person. Can you think of an
example of two systems and how they work together? Explain
your ideas.
Answer:
the lungs and heart give oxygen to the cells and the sensory system gives messages to the brain
Explanation:
The force of attraction that holds two atoms together within a molecule is
A
thermonuclear bonding
B
chemical bonding
crystal bonding
D
an atomic number
The mixtures of sodium carbonate and calcium nitrate react to participate calcium carbonate and sodium nitrate. This reaction is shown by which balanced chemical equation?
Explanation:
Na2CO3+Ca(No3)2---> CaCO3+2NaNo3
please helpp: All things that are acidic will eventually produce ___ in an aqueous solution?
Answer:
Protons / H+ ions
Explanation:
The acids are compounds with a pH range between 1-7, while the base has a pH range of 7-14. Acids produce hydrogen ions or protons in the solution.
What is pH?The pH can be defined as the hydrogen ion concentration in the solution. The higher the proton concentration in the solution, the lower will be the pH.
The pH of 7 has an equal number of hydrogen and hydroxide ions contributing to the neutral pH. The alkaline pH is contributed by the hydroxide ion concentration.
The acids fall at the lower pH range with a high hydrogen ion concentration. Thus, acids produce hydrogen ions or protons in the aqueous solution.
Learn more about acids, here:
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What do glycine, leucine, and lysine all have in common?
They are the building blocks of proteins.
They have an important role in the heart.
They have a role in the functioning of the stomach.
They store equal amounts of energy in their bonds.
Answer:
a, they are the building blocks of proteins.
Explanation:
hope this helps!
~mina
Answer:
A. They are the building blocks of proteins.
(Photo for proof at the bottom.)
Explanation:
Glycine, leucine, and lysine are all amino acids. There are 20 different kinds of amino acids, including the 3 mentioned here. Different amino acids bond together to form different structures, depending on how many there are. Generally, 50 or more amino acids bonded together makes a protein. But there are some exceptions. Amino acids (including glycine, leucine, and lysine) are the building blocks of proteins.
Here's a photo of Edge incase you're doubtful.
Please click the heart if this helped.
The percent yield for the reaction in which 15.6g of aluminum hydroxide is reacted in excess hydrogen chloride gas is 92.5%. What is the actual yield of aluminum chlorine?
Answer:
24.6 g
Explanation:
um...id.k how to do chemistry...help please?
Answer:
NaBr
Explanation:
Answer:
um...id.k how to do chemistry...help please?
Explanation:
NaBr
3. Define the following:
a. electromagnetic radiation
b. wavelength
c. frequency
d. quantum
e. photon
How does this equation show that transmutation has taken place? 238 U – 334 Th + He 92 O A. The numbers of neither nucleons nor atoms are conserved. B. One element changes into another. O C. Atoms of different elements are present. O D. The number of nucleons is not conserved.
Answer:
B. One element changes into another.
Explanation:
We can see from the equation that uranium is changed to thorium and helium. Transmutation is the process by which one element is changed to another through radioactive decay, nuclear bombardment, or other similar processes.
Answer:b
Explanation:
What does it mean to say that scientific models are open to change? (2 points)
a
Scientific models are usually not very accurate.
b
Scientific models can be adjusted when new information is found.
c
People can adjust scientific models to fit their personal beliefs.
d
Experimental results can be changed to fit the accepted model
please help I'm stuck
7. Which of the following correctly defines an acid-base reaction?
a. redox reaction
b. neutralization reaction
C. combustion reaction
d. hydrolysis reaction
Answer:
b
Explanation:
What is the pH of a solution that has 7.8x10-9 [H+]?
Answer:
8.11
Explanation:
pH = -log[H+]
pH = -log[7.8 x [tex]10^{-9}[/tex]]
pH = 8.107905...
pH = 8.11
Use the following words to fill in the text (can be used more than once).
Anode,Anode to cathode,Battery,Cathode,Chemical to electrical,Electrical to chemical,Electrolysis,Electroplating,Endothermic,Exothermic,N/A
Negative,No,Non-Spontaneous,Oxidation,Positive,Reduction,Spontaneous,Yes.
Answer:
VOLTIC CELL
Battery
Electrical to chemical
Endothermic
Electrolysis
Chemical to electrical
Anode
Anode to cathode
Battery
Endothermic
Negative
Enthomeric
Reduction
Oxidation
ELECTRYOTIC CELL
No
Non spontaneous
positive
negative
yes
Anode
Electrical to chemical
Anode to cathode
Exothermic
positive
oxidation
Electroplating
Chemical to electrical
Define the functions of the parts of a solar panel. I Will give Brainly and Venmo 5 bucks it's for a project lol. Without copy and pasting! The reason why it's low points is that people aren't actually answering please don't be that person.
Aluminum Frame-
Tempered Glass-
EVA-
Solar Cells-
Back Sheet-
Junction Box-
Answers:
Aluminum Frame - The aluminum frame is used to protect all the parts of the solar panel. It basically works as a shield against damaging items (hail, ice.)
Tempered Glass - The tempered glass keeps pressure inside the solar panel and keeps compressure outside of the solar panel to protect it from breaking.
EVA - EVA is a great alternative for electric radiational heat. It has a small amount of degradability to sunlight which keeps the panel from burning.
Solar Cells - Solar Cells are the part of the solar panel which work to transform the solar energy into electricity and not just use raw sunlight.
Back Sheet - Back sheets keep solar cells and the top and the bottom of the panel together. They make sure nothing inside the panel comes off.
Junction Box - The junction box makes sure all the solar cells inside of the solar panel are kept together so that the machine works as a whole and the back sheet's function does not get destroyed.
how much current would be measured in a circuit if the light bulb has a resistance of 6 ohms and a voltage of 36 volts
Answer:
The right response is "6 A". A further explanation is given below.
Explanation:
The given values are:
Resistance,
R = 6 ohms
Voltage,
V = 36 volts
As we know,
⇒ [tex]V=IR[/tex]
then,
⇒ [tex]I=\frac{V}{R}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{36}{6}[/tex]
⇒ [tex]=6 \ A[/tex]
Did Dalton believe that atoms could be created or destroyed? Explain
☁️ Answer ☁️
Yes.
"In so doing, he became the first scientist to explain the behavior of atoms in terms of the measurement of weight. He also uncovered the fact that atoms couldn't be created or destroyed. Dalton's theory additionally examined the compositions of compounds, explaining that the tiny particles (atoms) in a compound were compound atoms"
Hope it helps.
Have a nice day noona/hyung.